Mentions:
Chondrites Sternberg is considered as an infaunal deposit-feeding system [14]. It comprises a regularly branching tunnel system consisting of a small number of master shafts open to the surface, which ramify at depth to form a dendritic network [14–17]. In the present paper, we describe four different species of Chondrites from the Barakar Formation, namely, Chondrites patulus (from Kudaposi Nala), Chondrites targionni (from both Kudaposi Nala and Khudia Nala), Chondrites affinis (from both Kudaposi Nala and Khudia Nala), and Chondrites recurvus (from Khudia Nala). In both the study sections, all the ichnoforms are hosted in fine-grained, massive claystone, mostly preserved as epichnial, sand/silt-filled ridges on the claystone bedding surfaces. The following is a description of all the ichnospecies recorded from the two areas under study.

Mentions:
Chondrites Sternberg is considered as an infaunal deposit-feeding system [14]. It comprises a regularly branching tunnel system consisting of a small number of master shafts open to the surface, which ramify at depth to form a dendritic network [14–17]. In the present paper, we describe four different species of Chondrites from the Barakar Formation, namely, Chondrites patulus (from Kudaposi Nala), Chondrites targionni (from both Kudaposi Nala and Khudia Nala), Chondrites affinis (from both Kudaposi Nala and Khudia Nala), and Chondrites recurvus (from Khudia Nala). In both the study sections, all the ichnoforms are hosted in fine-grained, massive claystone, mostly preserved as epichnial, sand/silt-filled ridges on the claystone bedding surfaces. The following is a description of all the ichnospecies recorded from the two areas under study.

Bottom Line:
Rhythmic sandstone-mudstone-coal succession of the Barakar Formation (early Permian) manifests a transition from lower braided-fluvial to upper tide-wave influenced, estuarine setting.Monospecific assemblage of marine trace fossil Chondrites isp. in contemporaneous claystone beds in the upper Barakar succession from two Gondwana basins (namely, the Raniganj Basin and the Talchir Basin) in eastern peninsular India signifies predominant marine incursion during end early Permian.Such anoxia is interpreted as intermittent falls in oxygen level in an overall decreasing atmospheric oxygenation within the late Paleozoic global oxygen-carbon dioxide fluctuations.